Sweat Rash and Dhobie or Jock Itch
Sweat rash can affect the skin fold areas- where skin rests on skin and appears as a reddened area usually with a defined border. It may be worse in warm weather but can occur at any time of year.
Dhobie or Jock itch (tinea cruris) appears on the groin and inner thigh area, usually on both sides but often with one side more than the other, where it can spead further between the legs and the buttocks, or up towards the stomach. Dhobie itch looks like a clearly bordered rash, which may have blisters.